Dowel pin



Sept. 3, 1963 W. C. KERR DOWEL PIN Filed Nov. 18, 1960 FIG! Hulll lijm7o sesA INV EN TOR. WALTER C. KEER bluoufmf., McRAE Eme ATTO RN EYSUnited States Patent Oliice 3,1%,746 Patented Sept. 3, 1963 3,102,746DOWEL PIN Walter C. Kerr, 924 Oakwood, Dearborn, Mich. Filed Nov. 18,1960, Ser. No. 70,241 7 Claims. (Cl. 287-127) This invention relates toa :do-wel pin construction, land more particularly to a dowel pin whichfunctions to prevent relative shifting of two parts which are securedtogether.

In metal working, it is frequently desirable to secure two partstogether in such a manner as to prevent even minute shifting of one pa1trelative to the other. For example, in the making of dies and fixtures,mating parts may be secured together and machined. Relative shifting ofthe parts during such machining must be prevented in order to maintainthe parts within specified tolerances. Conventionally, the parts arefirst secured to each other by the use of clamps or screws. 'Registeringcircular openings are then provided in the parts and a cylindrical dowelpin is driven into and through each set of openings, a portion of thedowel pin extending into each pant. The dowel pin functions to preventshifting of the parts relative to one another.

This method of ldroweling h-as proved unsatisfactory in some instances.For example, it is frequently necessary to drill the dowel pin holesafter the two parts have been mounted in 1a fixture. If the doweledparts are part of a large structure, such as an automotive body fixture,pontalble drilling equipment must be used and it is Yfrequentlydiiiicult to accurately drill the holes. In addition, due to the limitedworking spiace available, the provision `of the holes is time consumingiand expensive (the service of highly skilled workmen such as tool anddie makers being necessary).

The dowel pin of the present invention permits forming ofthe dowel holesprior to `assembly `of the parts. As will be appreciated, this resultsin a significant amount of time saved, yand additionally, in som-ecases, improved accuracy.

It. is an object of the present invention to provide a dowel pinconstruction for holding two pants from relative shifting.

Another object of the invention is to provide such a dowel pin whichnecessitates the provision of an opening in only one of the parts, fandwherein the opening may be formed prior to assembly of the parts.

A further Iobject ofthe invention is to provide 1a dowel pin having asleeve structure with an extendable prong structure which is4insertalble into `a metal part for engagement therewith.

Other objects cf this invention will appear in the following descriptionand appended claims, reference being had to the accompanying drawingsforming a part of this specification wherein like reference charactersdesignate corresponding parts in the several views.

In the drawings:

FIGURE l is a side elevational View of 'one emb0diment of the dowel pinof the present invention with parts broken away for the purpose ofclarity;

FIGURE 2 is a bottom plan view of the dowel pin of FIGURE 1;

FIGURE 3 is a top plan View of the dowel pin vof FIG- URE l;

FIGURE 4 is an exploded view of the prong structure of the dowel pin ofFIGURE l FIGURE 5 is a view of two parts in which the dowel pin yofFIGURE l is utilized, the parts being clamped together and positioned ina fixture; and

FIGURE 6 is a sectional view of a second embodiment of the dowel pin inwhich the prong structure is modified. Before explaining the presentinvention in detail, it iS to be understood that the invention is notlimited in its ad application Ito the `details 'of construction andarrangement yof .parts `illustrated in the accompanying drawings, sincethe invention is capable of other embodiments yand of being practiced orcarried out in various ways. Also, it is to be understood that thephraseology or terminology employed herein is for the purpose ofdescription `and not of limitation.

As may be seen by reference to FIGURE 1, the dowel pin 1li includes asleeve 12 comprising `an elongated body having an opening .f4therethrough. An enlarged head 16 is provided at one end of the sleeve,the opening 14 being enlarged at this point to form a recess lli. Thesleeve is internally threaded, the threads extending from end 26 up tothe recess 13. The sleeve has a pair of diametrically :opposed slits 22,24 which also extend from end 26 up to head 16. The slits define opposedcompressible walls 62, 64.

Threadingly engaged in the sleeve is externally threaded member 28.Member 23 is provided with a fwrench engageable head 30 'at one end anda pointed prong element 32 `at the other end. The prong 32 extends intothe recess 1S. Received lin the recess is a circular sliding element 34.The sliding e-lement 34 has an opening 36 therethrough to receive theprong 32 with the tip 38 projectable therebeyond As will be noted inFIGURE 4, the element 34 is provided with a plurality of relatively smdlpointed prongs 4t) arranged around the outer periphery of face 42. Theprongs 40 are wed-ge shaped and |have relatively flat faces 4l, 43. The`faces 41, 43 are substantially parallel to the longitudinal taxis ofthe pin structure 10. When the prongs 4i) `are driven into a metalelement, as will be idescribed hereinafter, the faces 41, 43 will resistmoving out of engagement with the metal element when [forcesperpendicular to the dowel pin `axis are applied to the structure. lfthe prongs 4f) were conical, the 'tendency would be to move up thesloping surface formed by the prongs in the metal element upon theapplication of such perpendicular forces.

Use of the pin 10 is illustrated in FIGURE 5. As there shown, twomembers 44, 46 having flat faces 48, Si) 'are secured together by meansorf screws 52, 54 with the flat faces 48, in facial contact. Thisassembly is held in place by means of a fixture 56. One fof the members44 is provided with an opening 58 therethrough. The opening 58 is formedprior to the assembly of the parts. The opening is counterbored adjacentthe member 46 to form fa recess y47 for the reception of the head 16 ofthe dowel pin. The dowel pin 10 is inserted into the opening 58 beforethe members 44, 46 are secured together.

The opening 58 is of smaller diameter than the normal diameter of sleeve12. When the sleeve is driven through the opening, the Walls 62, 64 arecompressed towards each other with a consequent reduction of theinternal sleeve diameter. This provides a firm engagement betweenopening `58 and the sleeve and also -a firm engagecment of the threadedmember 2S with the threads of the sleeve. 'l'lhe net result is thatthere is a close fit between these three parts, which prevents sidewisemovement between the dowel pin and the member 44. This is advantageousin that the manufacturing tolerances, particularly of the threads, donot have to be held to an extreme degree of accuracy in order tomaintain a tight fit. A significant manufacturing cost saving isobtained by this construction.

After the parts have been assembled together, the head 30 of threadedmember 28 is turned by means of a wrench to thread the member 28 towardsthe doweled member 46. The member 28 will drive the prongs 4t) ofsliding :member 34 and the prong 32 into the doweled member 46 to thusengage this member and prevent its shifting relative to member 44.Normally, the prongs will be driven their full length into member 46.However, if it is desired to disassemble members 44, 46 and y kin recess70. However, there is no prong providedv on the end of the threadedmember 74. Instead, an enlarged prong 76 is provided centrally of thesliding member 72.

The slidingmember 72 is also provided with peripheral prongs 78 as inthe FIGURE l embodiment.

In operation, the inner end Sii of the threaded member abuts against:the sliding member '72 to drive thisv member into engagement with thedowel member.

When two parts have been doweled together by use of the dowel pin of thepresent invention, they may be handled and machined without danger ofsignicant relative shifting. There will always be, of course, a smallamount of shift.

opening therethrough to receive said pointed element with the tip of thepointed element projecting therebeyond, and a plurality of prongs on thesliding element extending outwardly from the recess.

2. ln-a dowel pin, the combination comprising a body having an openingtherethrough, an enlarged head at one end of the body, means including aprong structure received in the opening at the end of the body having anenlarged head, said body opening being internally threaded adjacent tothe enlarged head, and an externally threaded member threadingly engagedin said sleeve toV drive the prong ystructure out of the body.

3. A device as in claim 2 and further characterized in that the prongstructure means comprise a sliding element in said recess; and aplurality of prongs on the sliding element extending outwardly from therecess;

said externally threaded member abutting against the 5 However, with thepresent invention i such shifting can be kept approximately within close4 Y sliding element for driving the sliding element and prongs out oftlhe opening.

4. ln a dowel pin construction, the combination comprising an internallythreaded sleeve for insertion into an opening; the sleeve being slitlongitudinally to permit insertion thereof into an opening of smallersize than the sleeve with a consequent reduction of the internal sleevediameter; an enlarged portion at one end of the sleeve; a recess in theenlarged portion; means including a prong structure received in therecess, and an externally threaded member threadingly engaged in saidsleeve to drive the prong structure out of the recess.

5. A dowel pin construction comprising a body having an openingtherethrough; a portion of said opening being threaded; the openingbeing enlarged adjacent the threaded portion to form a recess; a'threaded member in threading engagement with the threaded portion of theopening; a pointed element carried on one end of the threaded member andextending into the recess; and

a sliding element in said recess; said sliding element having an openingtherethrough to receive said pointed element rwith the tip of theVpointed element projecting therebeyond.

6.- The combination comprising rst and second doweled members eachhaving a mating face with respect to the other and secured together withthe mating faces `in facial contact; a tirst one orf said members havingan opening therethrough; said opening being enlarged adjacent the seconddoweled member; a dowel pin in said opening; said dowel pin comprisingan internally threaded sleeve received Vin said opening and having anenlarged portion at one end thereof received in the enlarged portion ofsaid opening; a recess in the enlarged portion of the sleeve; meansincluding a prong structure received in the recess, and an externallythreaded member threadingly engaged in `said sleeve to drive the prongstructure out of the recess into engagement with said second doweledmember.

7. The combination of'claim 6` and further character-` ized in that theopening in the rst doweled member is smaller than the normal diameter ofthe dowel pin sleeve; the sleeve being slit longitudinally to permitinsertion thereof into the doweled member opening with a consequentreductionrof the internal sleeve diameter whereby to provide a tirrnengagement between the doweled member opening and the sleeve and betweenthe sleeve and said threaded member. e

References Cited in the file of this patent i UNITED STATES PATENTS750,211 Miner Jan. 19, 1904 913,575 Sprague Feb. 23, 1909 r945,863 PaughJan. l1, 1910 4,438,648 Jacobs Dec. l2, 1922 2,901,787 Whistler et al.Sept. 1, 1959

2. IN A DOWEL PIN, THE COMBINATION COMPRISING A BODY HAVING AN OPENINGTHERETHROUGH, AN ENLARGED HEAD AT ONE END OF THE BODY, MEANS INCLUDING APRONG STRUCTURE RECEIVED IN THE OPENING AT THE END OF THE BODY HAVING ANENLARGED HEAD, SAID BODY OPENING BEING INTERNALLY THREADED ADJACENT TOTHE ENLARGED HEAD, AND AN EXTERNALLY THREADED MEMBER THREADINGLY ENGAGEDIN SAID SLEEVE TO DRIVE THE PRONG STRUCTURE OUT OF THE BODY.